Inspiration for artifacts in Cidri
 

A couple of older stories that could be updated or modified to introduce powerful artifacts into Cidri. Powerful, but transitory.

"The 7th Is Made Up of Phantoms" The Twilight Zone
"The Doomfarers of Coramonde" Brian Daley

Both introduce modern armored vehicles and weapons with their crews into simpler worlds. In the one, the tank breaks down before it can interfere in the "Last Stand". In the second, the vehicle and crew are brought to an alien world to challenge a dragon. The first would be a temporal anomaly of some kind or perhaps a gate left open. The second, a spell gone either really right or really wrong.

In either event, while they could be enormously powerful for a short period of time, they would rapidly become immobile through lack of fuel or breakage and running out of ammunition or having the ammunition rendered defective. But still, it is interesting.

Re: Inspiration for artifacts in Cidri
 

For a similar situation, see the 'Castaways in Time' series by Robert Adams, in which some modern folks on a hunting trip get transported to medieval Britain — along with their modern toys, including not only their guns but a couple of jeeps.

As you would expect, those modern toys don't last forever, but they give the characters an enormous initial advantage.

And then they exploit their modern scientific knowledge, which proves far more valuable in the long run.

Re: Inspiration for artifacts in Cidri
 

And, it would fit in with the overall zeitgeist of Cidri, where you can find artifacts like a .45 caliber pistol and old ball point pens -- implying it's already happened more than once. I once did a campaign where it started with my players in a well-equipped hunting trip up to Montana (where they were taking a friend some reloading equipment and supplies en route), and along the way they accidentally drove through a gate into Cidri...

Re: Inspiration for artifacts in Cidri
 

https://www.imdb.com/title/tt0080736/ Modern aircraft carrier at Pearl Harbor, they cop out in the end, so no F16 vs Zero dogfights. A disappointment, more of a warning than a spoiler.

https://www.amazon.com/Guns-South-No.../dp/0345384687 - Guns of the south - AK-47's change the Civil War.

The challenge would be to selectively apply the technology and leverage the effect before the fuel/ammo runs out.

Re: Inspiration for artifacts in Cidri
 

Also, the 1979 Sonny Chiba film Sengoku Jieitai (variously called "Time Slip" or "G.I. Samurai" in English), in which a group of modern JSDF soldiers are transported back to the Warring States period. With a tank and a helicopter, among other things.

Or even better, check out the 2015 anime Gate, in which a Gate (of the magical kind) is opened between modern Japan and a fantasy world with magic, dragons, and medieval tech levels. That one's a bit different from the usual situation, because the Gate stays open — which means the modern folks can resupply, and pour as many troops into the other world as they want.

Two of the more memorable scenes in Gate: Breaking the siege of a castle by strafing the attackers with Apache attack helicopters, and putting down a dragon with a couple of F-4 Phantoms.

Re: Inspiration for artifacts in Cidri
 

Personally, I prefer to make Mnoren artifacts more cryptic. Not magical, but mysterious and unclear as to their use and function. More along the lines of numenera from the Numenera RPG.